1.Derived from Ayatollah which is Arabic for "sign of God," but in a more sensible English version of the word. Also more practical and modern than the original.
2. A Great One, or one who is a master of a trade or skill set. What is more a sign of God than one who's expertise exceeds the skills of most men or women who try to do the same thing.

Chris Jericho is the Iotolah of Rock-N-Rolla! He is a master of his trade not an Iranian Cleric. Jimi Hendrix was a master of rock, clearly an Iotolah of the guitar.